52 | New Scientist | 21/28 December 2019I
N THE late 1960s, Aradio Rodaniche was
diving off the coast of Nicaragua when
he made the discovery that has tantalised
cephalopod biologists ever since.
Not only was the octopus he found
startlingly beautiful – another biologist later
said it was the most beautiful he had ever
seen – but it was living in a den with others of
its kind. That was unheard of. Octopuses are
undoubtedly remarkable creatures: they can
solve puzzles, use tools and even mimic other
species. They have three hearts and multiple
brains, with an intelligence rivalling that of
famously smart animals such as crows and
apes, and their visual communication abilities
are mysterious and beguiling. But the octopushad always been considered a solitary beast.
The discovery of an apparently social species
was so implausible that few believed it and
Rodaniche’s story passed into legend. He
published a short account of the species in
1991, but hardly anyone had seen the animal
and no one could confirm the report. It didn’t
help that the octopus has never been officially
described (see “Nameless wonder”, below).
Gradually, the situation is changing. Work
is emerging that confirms what Rodaniche
originally suspected. The animal, referred
to only as the larger Pacific striped octopus
(LPSO), does seem to be a social species, and
a couple of other types of octopus have
now been discovered that also show socialbehaviour. Beyond the breathless prospect of
octopus communities with hive minds even
smarter than any of their members, these
breakthroughs indicate it is time for us to
reassess these fascinating creatures.
The LPSO is a small animal, with a striped
body about 7 centimetres long and spotted
arms that make it look like it is wearing a
polka-dot dress. It lives at depths of up to
300 metres in the eastern Pacific Ocean,
in regions with sandy and muddy floors.
Unlike most other octopuses, female
LPSOs don’t die after laying their eggs. They
also share dens with others of their species,
sometimes in groups of up to 40. “LPSOs live
about two years and females lay eggs over
a period of a year,” says Roy Caldwell at the
University of California, Berkeley. “I think the
apparent social nature of this species has to
do with the habitat in which they are found,”
he says. “Dens are hard to come by and may
be clumped, leading to close interactions
among individuals.”
Caldwell and his team found that denning
sites persevered for longer than the lifespan
of an individual. This seems to be because, on
the sandy and muddy sea floor that is typical
of LPSO habitats, suitable spots are few and
far between. The biologists don’t label them
as such, but it is tempting to think of the
persistent aggregations as octopus villages.
Christine Huffard at the Monterey Bay
Aquarium Research Institute in California is
one of the scientists who worked with Caldwell
to confirm Rodaniche’s original observations.
“They hold significant mystery,” she says,
picking out another behaviour unique to
LPSOs: their habit of mating face to face (or
more accurately, beak to beak) with their
arms entangled. “The LPSO mating system
made us rethink what we consider possible for
octopuses to do,” she says. “Males and femalesCephalopods were supposed to be solitary animals,
says Rowan Hooper. It turns out that some like company
It is odd that the larger
Pacific striped octopus
(LPSO) has no scientific
name. Its discoverer,
Aradio Rodaniche,
sent specimens to the
Smithsonian Institute
in the late 1960s, where
researchers started a
formal description and
gave it the name Octopus
spilotis. Rodaniche
referred to this
description as “in press”,
but it was never
published. Roy Caldwell
at the University of
California, Berkeley, says
he suggested to another
cephalopod biologist,Eric Hochberg at the Santa
Barbara Museum of
Natural History, that LPSO
be named for Rodaniche.
Sadly, Hochberg didn’t get
round to doing it before he
retired, so the spectacularanimal remains nameless.
That’s a shame, because
Hochberg was a great
namer. A stunning octopus
he found in 2006 (below)
was aptly christened
Wunderpus photogenicus.Nameless wonder
Eight legs, three
hearts and no friends?
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